JP2006337985A - Method of manufacturing high sag lens and lens manufactured by using the same method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing high sag lens which improves lens quality because the correction of a lens surface resulting from polymer shrinkage is not required and drastically increases work productivity because the manufacture without repeated replication is possible. <P>SOLUTION: There are provided a method of manufacturing high sag lens and a lens manufactured by using the method. The method of manufacturing high sag lens, in which a polymer lens part made of ultraviolet (UV) curable resin is formed on a substrate, comprises: a process (a) of injecting polymer into a mold formed of a large number of grooves and curing the polymer by UV ray to form a large number of lens parts; a process (b) of integrally adhering the substrate to a back surface of the lens part; and a process (c) of releasing the mold from the lens part to produce an lens array. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens manufacturing method having a high sag and a lens manufactured using the same. More specifically, since the lens surface is not compensated for by polymer shrinkage, the lens quality is improved, and the replica method is used. The present invention relates to a method for manufacturing a high sag lens that can be manufactured without repetition, and can dramatically increase work productivity, and a lens manufactured using the same.

  Conventionally, a lens array is manufactured directly through a laser beam or the like, or a lens array is formed by using an etching process or a reflow method using a pattern, and using such a lens array, Ni plating (electro- After manufacturing a Ni master mold through the plating method, a lens array has been manufactured using a replica method, a molding method, or the like for the Ni master mold.

  As another method, a diamond turning machine (DTM) is used to manufacture a lens mold, which is expanded to an array, and then a replica array or a molding method is applied to manufacture a lens array. However, when using such conventional methods, there are the following restrictions.

  That is, when processing a mold with a laser beam, the sag of a lens that can be manufactured is proportional to the thickness of the photoresist (PR) layer formed after spin coating, so that a high sag, that is, a high sag of several hundred μm, is obtained. It is difficult to manufacture a lens having (sag).

  In addition, there is a limit to the aspherical surfaces that can be produced with difficulty in forming an aspherical surface during molding with a laser beam.

  Conventionally, as shown in FIG. 1, in order to form the high sag lens 200, the replica method has to be repeatedly molded many times. In this way, the replica method is repeated two or more times so that the lens portion 210 is formed on the substrate 205. In the case of manufacturing, a lot of work time is required by repeating the entire process, for example, a replica process such as polymer drop, compression, UV curing, and release.

  In addition, such a replica method requires additional molds (not shown) having different NA (Numerical Aperture) values applied to the molding layers 210a, 210b, and 210c of the respective lenses.

  On the other hand, FIG. 2 shows a conventional process 300 in which a photopolymer is applied once to a metal plate, covered with a substrate, and then immediately cured to manufacture a lens array.

  In the conventional technique, first, a step of dropping a photopolymer 310 on the MLA mold 302 is performed, and a step of bonding a transparent substrate 315 on the photopolymer 310 to form a lens portion is performed. The step of curing the photopolymer 310 by irradiating ultraviolet rays (UV) is performed, and then the MLA mold 302 is separated from the lens unit 320 to manufacture a lens array.

  FIG. 3 shows a manufacturing process 400 of a lens array having a different form.

  In the conventional technique, a mold 405 having one groove 405a corresponding to a convex lens is prepared. A UV curable resin is applied to the groove of the mold 405 to form a lens portion 410. After the step of bringing the substrate 412 into close contact with the back surface and the step of irradiating the ultraviolet ray through the substrate 412 to cure the UV curable resin, the mold 405 is removed and the lens unit 410 and the substrate made of the UV curable resin are removed. 412 is obtained, and a lens array (MLA) 420 is manufactured by repeatedly arranging them in parallel.

  However, in such a conventional technique, in the manufacturing process, as shown in FIG. 4, the curing of the polymer starts from the substrate 315, 420 side and proceeds to the lens surface P side farthest from the substrate 315, 420. For this reason, at the end of curing, there is a problem that the polymer shrinkage is concentrated on the round spherical lens surface P side and the curvature and form thereof become poor.

  In addition, bubbles B may be generated during the curing of the polymer forming the lens portion. If such bubbles are generated, the bubbles are not discharged to the outside by the transparent substrates 315 and 412, and the inside of the lens portions 320 and 410. May cause a problem in lens quality.

  Therefore, in the process of manufacturing a high sag lens, the lens surface is not compensated so that the polymer shrinkage occurs in a place other than the lens surface, and no bubbles remain inside the lens. It is a problem to greatly improve.

  Further, since it is possible to manufacture a lens array without repeating the Replica method, it is a problem to dramatically increase work productivity.

  In order to solve the above-mentioned problems, in the first embodiment of the present invention, in a method for manufacturing a lens in which a polymer lens portion containing an ultraviolet (UV) curable resin is formed on a substrate, a) a polymer is injected into a groove of a mold Curing the substrate with ultraviolet rays to form a lens part, b) adhering and integrating the substrate to the back of the lens part, and c) separating the mold from the lens part to produce a lens. The manufacturing method of the high sag lens characterized by this is provided.

  Preferably, the step of forming the lens unit provides a method for manufacturing a high sag lens, wherein the lens unit is cured in air or in an oxygen atmosphere.

  Preferably, the step of forming the lens portion includes a process of separately injecting a polymer into the groove of the mold and repeatedly curing with ultraviolet rays.

  Preferably, the method for producing a high sag lens is characterized in that in the step of integrating the lens part and the substrate, the adhesive used is the same composition as the polymer forming the lens part.

  Preferably, in the method for producing a high sag lens, in the step of integrating the lens part and the substrate, the adhesive used is a composition having optical characteristics similar to the polymer forming the lens part. To do.

  Preferably, in the step of integrating the lens unit and the substrate, a high sag lens manufacturing method is provided, wherein the polymer forming the adhesive is cured by ultraviolet rays irradiated through the substrate.

  In order to solve the above-described problem, in a second embodiment of the present invention, a lens generated by the above-described method for manufacturing a high-sag lens is provided.

  According to the present invention, in the process of manufacturing a high sag lens, it is possible to mold a high sag lens at a time using a mold using a DTM, and the lens portion is cured while being exposed to the atmosphere. Therefore, the shrinkage of the radical reaction due to oxygen is caused so that the polymer contraction occurs from a place other than the lens surface, and the lens surface does not need to be compensated.

  In addition, it is possible to prevent the bubbles that may be generated during the curing of the polymer from remaining inside the lens portion, and as a result, the quality of the lens can be greatly improved.

  In addition, according to the present invention, since the replica method is not repeated, many polymer drops, compression, UV curing, release, etc. are unnecessary, and various shapes are added. A special mold is unnecessary, and the lens array can be manufactured with a simple process, so that the production productivity of the high sag lens can be dramatically improved.

  In addition, the present invention also has an effect that a high-sag lens working Ni master mold can be easily obtained by applying an Ni-plating method to the lens array obtained as described above.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 5a, 5b, and 5c, a high sag lens manufacturing method 1 according to the present invention is as follows. A step of forming the lens unit 20 is performed.

  Since the mold 10 is processed by DTM, an aspherical lens can be easily manufactured and a lens having a large sag can be manufactured. That is, the grooves 10a and the like formed in the mold 10 have a height of several hundreds μm and can have a depth of a high sag lens at a time by a single molding operation.

And when the polymer 15 is inject | poured into the said mold 10, the curing process is carried out with an ultraviolet-ray in the state in which the surface of the polymer 15 was exposed to air | atmosphere. In such a case, the polymer 15 and the like positioned in the groove 10a of the mold 10 suppresses a curing phenomenon by suppressing radical reaction (Radical Reaction) due to oxygen (O ₂ ) in the air at the interface with the air, and the polymer 15 is cured. Is done the latest.

That is, in the curing process of the lens unit 20, the curing of the polymer 15 is the slowest due to the action of oxygen (O ₂ ) at the exposed interface between the atmosphere and the exposed surface of the polymer 15 instead of the lens surface P. Performed from above P ′.

  That is, as illustrated in FIG. 6, curing is performed from the portion of the lens surface P that is in contact with the groove 10 a of the mold 10, and the curing progresses gradually to the exposed surface P ′ of the lens portion 20, thereby The polymer shrinkage portion generated from such a curing process gathers on the exposed surface P ′ of the lens unit 20 that has not been cured yet. Accordingly, in the final lens unit 20, the exposed surface P ′ is cured in a form reflecting all the polymer 15 contraction.

  Also, bubbles that can be generated inside the lens unit 20 from such a process can be freely discharged to the outside through the exposed surface P ′. Therefore, bubbles generated from the curing process of the lens unit 20 do not remain inside.

On the other hand, although it has been described above that the exposed surface P ′ of the lens unit 20 is exposed in the air, the present invention is not limited to this, and any oxygen (O ₂ ) capable of obtaining the same effect as air. It can be performed under an atmosphere.

  Further, in the above embodiment, it has been described that the lens portion 20 is molded in the groove 10a of the mold 10 by only one molding. However, the present invention is not limited to this. It is possible to form the lens portion 20 through a process in which a polymer is separately injected into the ten grooves 10a and repeatedly cured with ultraviolet rays.

  Then, in this embodiment, b) a step of bonding and integrating the substrate 25 to the back surface of the lens unit 20 is performed.

  Therefore, in this embodiment, the adhesive polymer 30 is applied on the lens portion 20 of the mold 10. Such an adhesive polymer 30 has the same composition as the polymer 15 forming the lens portion 20 or is made of a composition having similar optical characteristics.

  Examples of the similar optical characteristics may include those having a similar refractive index or Abbe number (Abbe's number). The adhesive polymer 30 is applied in a liquid state in a non-uniform form resulting from the shrinkage of the polymer 15 formed from the exposed surface P ′ of the lens unit 20 to form a layer to uniformly compensate for the non-uniformity of the exposed surface P ′. .

  In this state, the transparent substrate 25 is attached to the adhesive polymer 30, and the adhesive polymer 30 is cured by being irradiated with ultraviolet rays through the transparent substrate 25, and is attached to the substrate 25 integrally. .

  Even from such a process, the adhesive polymer 30 may shrink during the curing, and the generation of residual bubbles may be caused. However, since the adhesive polymer 30 is a small amount and its thickness is only a few μm, The shrinkage of the polymer and the generation of bubbles inside cannot affect the quality of the lens unit 20 in any way.

  Next, this embodiment includes the step of c) separating the mold 10 from the lens unit 20 and manufacturing the lens array 40.

  At this stage, the mold 10 is removed from the lens unit 20 to manufacture the lens array 40 in which a large number of lens units 20 are arranged on the side surface of the substrate 25.

  As described above, the manufacturing method 1 of the high sag lens according to the present invention uses the DTM to form the lens with the mold (mold) 10 in which the deep groove 10a is processed. Therefore, a high sag lens can be formed at a time. Is possible. Therefore, it is not necessary to repeat the replica method in which the molding layers are formed in a double layer and a triple layer in order to make a high sag lens, and accordingly, additional molds 10 having various shapes are unnecessary.

  Since the deformation due to the contraction of the polymer 15 is performed from another portion that is not the lens surface P, that is, from the exposed surface P ′, compensation for the shape distortion of the lens surface P is unnecessary, and accordingly, the quality of the lens unit 20 is improved. It is excellent and work productivity is very high.

  FIGS. 7a, 7b and 7c illustrate a high sag lens manufacturing method 100 according to another embodiment of the present invention. In the manufacturing method 100, first, a) a step of forming the lens portion 120 by injecting the polymer 115 into the groove 110 a of the mold 110 and curing it with ultraviolet rays is performed.

  At this stage, as described with reference to FIGS. 5a, 5 and 5c, the mold 110 is processed by DTM, so that an aspherical lens can be easily manufactured, the depth is increased, and the sag is increased. Large lens fabrication can be done.

  Then, after the polymer 115 is injected into the groove 110a of the mold 110, the polymer 115 is cured by ultraviolet rays in a state where the surface of the polymer 115 is exposed to the air. From this process, the polymer 115 in the groove 110a of the mold 110 is cured. Et al. Suppress the curing reaction by suppressing the radical reaction due to oxygen at the interface with air, and the polymer 115 is cured most slowly.

  Accordingly, the shrinkage effect generated while the polymer 115 is cured is transmitted to the exposed surface P ′ side of the uncured state, and the finally cured lens portion 120 has the exposed surface P ′ of all the polymers 115. Cured in a form that reflects cure shrinkage. Accordingly, the shape of the exposed surface P ′ is distorted. Also, bubbles that can be generated from the inside of the lens unit 120 from such a process are freely discharged into the air through the exposed surface P ′ and are not left at all inside.

  In the present embodiment, it has been described that the lens portion 120 is molded in the groove 110a of the mold 110 by only one molding as described above. However, the present invention is not limited to this, and when the high sag is very large, the groove of the mold 110 is formed. The lens part 120 can be formed through a process in which a polymer is separately injected into 110a and repeatedly cured with ultraviolet rays.

  Then, in this embodiment, b) a step of bonding and integrating the substrate 125 to the back surface of the lens unit 120 is performed. At this stage, as described with reference to FIGS. 5 a, 5 b and 5 c, an adhesive polymer 130 having the same composition as the polymer 115 of the lens unit 120 is applied on the lens unit 120 of the mold 110, and this is applied to the substrate 125. Adhere to the specified position. From this process, the adhesive polymer 130 is applied in a liquid state, so that the distorted form of the exposed surface P ′ is compensated and flattened.

  As described above, the lens unit 120 to which the adhesive polymer 130 is applied is disposed at a position determined around the alignment reference layer 135 formed on one side of the substrate 125.

  The alignment reference layer 135 is a thin film formed on the substrate 125 in advance, and provides a display line that allows the lens unit 120 of the mold 110 to be disposed at a predetermined position. Since the alignment reference layer 135 has a very small thickness, when the mold 110 having the lens unit 120 is attached to the substrate 125 through the adhesive polymer 130, any variation or influence on the adhesion amount of the adhesive polymer 130 is caused. It is impossible to give, only the alignment criteria are presented.

  Through such a process, the transparent substrate 125 is attached to the adhesive polymer 130, and the adhesive polymer 130 is cured by being irradiated with ultraviolet rays through the transparent substrate 125, and is attached to the substrate 125 integrally.

  Even in such a curing process, the adhesive polymer 130 may shrink and cause generation of residual bubbles. However, since the adhesive polymer 130 is a small amount and its thickness is only a few μm, such shrinkage is caused. And the generation of bubbles does not affect the quality of the lens unit 120 in any way.

  Next, c) separating the mold 110 from the lens unit 120 and manufacturing a lens is performed. That is, the mold 110 is removed from the lens unit 120 so that the lens unit 120 is formed on the side surface of the substrate 125.

  Next, d) the steps a) to c) are repeated, and the lens array 120 is manufactured by adhering and integrating a large number of lens portions 120 to the substrate 125. That is, the polymer 115 is injected into the groove 110a of the mold 110 and cured by ultraviolet rays to form the lens part 120. The substrate 125 is bonded and integrated on the back surface of the lens part 120, and the mold 110 is separated from the lens part 120. A series of steps are repeated, and a large number of lens portions 120 are adhered to the alignment reference layer 135 of the substrate 125 to form an aligned lens array 140.

  Through this process, according to the present embodiment, the compensation of the lens surface P due to the shrinkage of the polymer 115 is unnecessary, it is not necessary to repeat the replica method, and additional molds of various shapes are unnecessary, so that work production is possible. It is possible to produce high sag lenses with very high quality and excellent quality.

  FIG. 8 shows a high sag lens 150 obtained through the manufacturing methods 1 and 100 of the high sag lens of this embodiment as described above.

  Such a lens 150 is formed by injecting polymers 15 and 115 into molds 10 and 110 and curing them with ultraviolet rays, and substrate portions 25 and 125 on which the lens portions 20 and 120 are disposed on the side surfaces. Adhesive polymers 30 and 130 for integrating the lens portions 20 and 120 with the substrates 25 and 125 are included.

  FIG. 8 shows a structure in which a large number of the lens portions 20 and 120 are arranged on the substrates 25 and 125 and have the form of a lens array. However, the present invention is not limited to this, and one lens portion is formed on the substrate. It is also possible to consist of a single lens.

  Such a high sag lens 150 of the present invention has a sag height h of at least several hundred μm, as shown in FIG. 8, and polymers 15 and 115 forming the lens portions 20 and 120. The polymers constituting the adhesive polymers 30 and 130 have the same composition, and after curing, no boundary surface is formed between the adhesive polymers 30 and 130 and the lens portions 20 and 120, and they are formed integrally.

  In addition, the lens portions 20 and 120 are formed by a single molding in the grooves 10a and 110a of the molds 10 and 110, or when necessary, by separately injecting polymer into the mold grooves and repeatedly curing with ultraviolet rays. As a result, the unevenness of the exposed surface P ′ of the lens portions 20 and 120 generated during the curing process is all compensated uniformly from the formation process of the adhesive polymers 30 and 130.

  Therefore, any deformation due to the shrinkage of the polymers 15 and 115 does not occur on the lens surface P, and bubbles are not present in the lens portions 20 and 120, and the quality is very excellent.

  According to the present embodiment, it is possible to obtain a Ni master mold by applying a Ni plating (electro-plating) method on the lens array obtained from the manufacturing method of the high sag lens of the present invention as described above.

  In other words, conventionally, a lens array is formed directly through a laser beam or the like, or a pattern is used to form a lens array by an etching process or a reflow method, and Ni plating (electro-plating) is performed using such a lens array. The Ni master mold was manufactured through the method. However, if the Ni-plating method is applied to the lens array obtained from the manufacturing method of the high sag lens of the present invention, it is possible to easily obtain the Ni master mold that produces the high sag lens. It is.

  From the foregoing, the present invention has been illustrated and described with respect to particular embodiments, but this is merely illustrative for the purpose of illustrating the present invention and is intended to limit the present invention to such specific structures. is not. Those skilled in the art can make various modifications and changes without departing from the spirit and scope of the present invention described in the following claims. is there. However, it will be apparent that all such modifications and variations are within the scope of the present invention.

It is a detailed sectional view illustrating a high sag lens according to a conventional technique. It is explanatory drawing which illustrated in steps the lens manufacturing method with a prior art. It is explanatory drawing which illustrated in steps the lens manufacturing method of the other process accompanying a prior art. It is explanatory drawing which illustrated in order the hardening procedure of the lens part in the lens manufacturing method with a prior art. It is explanatory drawing which illustrated in steps the manufacturing method of the high sag lens accompanying one Example of a present Example. It is explanatory drawing which illustrated in steps the manufacturing method of the high sag lens accompanying one Example of a present Example. It is explanatory drawing which illustrated in steps the manufacturing method of the high sag lens accompanying one Example of a present Example. It is explanatory drawing which illustrated the hardening procedure of the lens part in order in the lens manufacturing method of a present Example. It is explanatory drawing which illustrated in steps the manufacturing method of the high sag lens accompanying the other Example of a present Example. It is explanatory drawing which illustrated in steps the manufacturing method of the high sag lens accompanying the other Example of a present Example. It is explanatory drawing which illustrated in steps the manufacturing method of the high sag lens accompanying the other Example of a present Example. It is detailed sectional drawing which illustrated the high sag lens obtained from the lens manufacturing method of a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Manufacturing method of high sag lens according to the present invention 100 Manufacturing method of high sag lens according to the present invention 10 Mold 110 Mold 10a Groove 110a Groove 15 Polymer 115 Polymer 20 Lens portion 120 Lens portion 25 Substrate 125 Substrate 30 Adhesive polymer 130 Adhesive polymer 135 Alignment reference layer (Alignment Layer)
40 Lens array 140 Lens array 150 High sag lens 200 of the present invention Conventional high sag lens 205 Substrate 210 Lens portion 210a Molded layer 210b Molded layer 210c Molded layer 300 Conventional lens array manufacturing process 400 Conventional lens array manufacturing process 302 MLA mold 310 Photo Polymer 315 Transparent substrate 405 Mold 405a Groove 410 Lens portion 412 Substrate 420 Lens array P Lens surface P ′ Exposed surface

Claims (7)

  In a method of manufacturing a lens in which a polymer lens portion containing an ultraviolet (UV) curable resin is formed on a substrate, a) a step of injecting a polymer into a groove of a mold and curing with ultraviolet rays to form a lens portion; b) the lens portion A method of manufacturing a high sag lens, comprising the steps of: adhering a substrate to the back surface of the lens and integrating the substrate; and c) separating the mold from the lens portion to manufacture a lens.   2. The method of manufacturing a high sag lens according to claim 1, wherein in the step of forming the lens portion, the lens portion is cured in air or in an oxygen atmosphere.   2. The method of manufacturing a high sag lens according to claim 1, wherein the step of forming the lens part includes a step of injecting a polymer separately into the groove of the mold and repeatedly curing with ultraviolet rays.   2. The method of manufacturing a high sag lens according to claim 1, wherein in the step of integrating the lens part and the substrate, the adhesive used has the same composition as the polymer forming the lens part.   2. The method of manufacturing a high sag lens according to claim 1, wherein in the step of integrating the lens part and the substrate, the adhesive used is a composition having optical properties similar to the polymer forming the lens part. .   The method of manufacturing a high sag lens according to claim 1, wherein in the step of integrating the lens unit and the substrate, the polymer is cured by ultraviolet rays irradiated through the substrate.   A lens manufactured from the method for manufacturing a high-sag lens according to claim 1.

Images